The present invention relates to a trolley for sliding sashes in windows and door-windows.
Current sliding sashes in windows and door-windows are provided with wheels mounted in a fixed position in the lower crosspiece of the sashes.
On the contrary, the upper crosspieces of the sashes are provided with a groove into which a guide bar integral to the upper crosspiece of the fixed window frame is inserted.
The assembling of the sashes takes place during the step of installation of the windows, so that once a window has been positioned, it is no longer possible to disassemble the sash, unless the whole fixed window frame is disassembled.
This is an important drawback when it is necessary to replace the pane of glass of a sash.
A further drawback pertaining to the sashes of known type consists in that it is not possible to execute any adjustment of the position of the wheel relative to the sash in order to eliminate possible plays between the sash and the fixed frame and to eliminate possible differences in the squaring between the sash and the fixed frame.
In the case of aluminum fixed frames a wedge-shaped device has been provided which acts on the wheels to adjust the squaring of the sash relative to the fixed frame, but said device only allows very little shiftings ranging from one to two millimeters and therefore it cannot be used for assembling and disassembling sashes from window frames.